Door closer



H w. FALK DOOR CLOSER 7 Jan. 12, 1960 Filed Oct. 5. 1956 INVENTOR Hare/a14/. a//1 ATTORNEY United States Patt DOOR CLOSER Harold W. Falk,Minneapolis, Minn. Application October 5, 1956, Serial No. 614,250 3Claims. (Cl. 16-66) This invention relates to an improvement in doorclosers and deals particularly with a means of pretensioning the doorcloser so that it will act properly when installed.

In the construction of door closers of the type used to close screendoors and the like, it is necessary that the closer be mounted so thatthere is some closing tendency on the door after it has been closed soas to insure the proper operation. As the springs which are used toclose the door are quite powerful due to the short leverage which isemployed, it is diflicult to mount the closer in place while the springis under tension. It is possible to mount one bracket upon the doorframe and to mount another bracket on the door at a predetermineddistance from the first bracket and to measure the distance so that theclosure plunger is not at its extreme position when the door is fullyclosed. However, it is much simpler to provide some means of holding theplunger in a proper position as it is mounted so as to insure the properrelationship between the supporting brackets.

In the past this has been accomplished through the use of a spring clipwhich partially encircles the plunger rod and holds the plunger frommoving into its extreme position toward which it is urged by the spring.This clip is maintained in place while the closer is mounted so thatthere is a constant tension against the door when it is fully closed.When the closer has been mounted, the'door is swung toward open positionand the spring clip removed. After the spring clip has been discarded,it does not form a stop to remove tension from the closer when the dooris closed.

While this structure operates effectively for its intended purpose, theuse of such a clip comprises an additional expense in the manufacture asthe clips are only useful until the door is mounted and are thendiscarded. It is an object of the present invention to provide a meansof eliminating this extra expense while still accomplishing the sameresults.

In a closer of the type described, an angular bracket is provided whichis slidable on the plunger rod. This bracket has a laterally extendingarm engageable with an end of the closer. When the closer engages thisarm it pivots the angle member on the plunger rod so that the anglemember will not move and so that the angle member forms a stop for thecloser casing. By providing suitable indicia on the plunger rod, it ispossible to pull the rod outwardly until a suitable mark is uncovered,to place the angle member at this mark, and to permit the plunger rod tomove into the cylinder until it engages the angle member. At this pointthere is the proper tension upon the spring within the cylinder tomaintain the door in closed position and the closer may be mounted whilethe plunger rod is in this position.

A feature of the present invention resides in the fact that the mark, ormarks, on the plunger rod may be in the form of grooves or slightindentations in the rod to provide a positive engagement between theangular bracket and the rod. As the bracket is held in an 2 adjustedposition by friction, there is a slight possibility that the bracketwill slide slightly after it is adjusted. By providing slight notches orgrooves in the piston rod into which an edge of the angle member mayengage, any such difliculty may be avoided.

An added feature of the present invention resides in the fact that therod may be provided with a series of notches so that the tension of thespring may be set in accordance with the weight of the door to beoperated by the closer. In other words, if the door to be closed isrelatively heavy and requires considerable force to close, the initialtension upon the spring. may be increased by initially placing the anglemember in one predetermined position. If the door is of medium weight,the angle member may be set at an intermediate position. If the door isextremely light-such as certain of the aluminum doors, less initialtension is required and the angle member may be set at a thirdpredetermined position.

A further feature of the present invention resides in the plungerconstruction which is employed. During recent years plungers have beenequipped with a pair of washer-like discs between which an O-ring islocated. Diificulty has been experienced in arranging these rings sothat movement of the plunger in one direction is relatively unimpededwhile movement of the plunger to provide a space between these in theopposite direction is definitely checked; In the present constructionthis dificulty is eliminated by providing an aperture in the plungerwasher on the side of the plunger opposite the closer spring and inproviding a space between the washers inwardly of the O-ring. As theplunger moves toward closed position, air trapped within the plungerflows through the opening in the washer and outwardly against the O-ringtending to expand the O-ring against the cylinder surface. Upon movementof the closer to open the door, suction created behind the plungertendsto reduce the diameter of the O-ring and to permit the door to be easilyopened.

A further feature of the present invention resides in the provision ofan automatic valve capable of opening if the pressure in the closed endof the closer becomes excessive. To accomplish this result, the plungerincludes a pair of washers, one of which is offset so as washers attheir periphery and between which the O-ring extends. The washeradjoining the flat washer of the pair comprises a flat flexibleresilient washer of cork or other suitable material. A reinforcingwasher sandwiches the flexible washer between the second washer of thepair and the reinforcing washer. The spring acts against the reinforcingwasher and normally holds the flexible washer against the O-ringsupporting washers. However, one or more small openings are providedthrough the flat washer of the pair and if the pressure within theclosed end of the cylinder exceeds the spring pressure, the pressure ofair through this passage may be suflicient to flex the flexible washerand to permit the escape of the excess air.

These and other objects and novel features of the present invention willbe more clearly and fully set forth in the following specification andclaims.

In the drawing forming a part of the specification:

Figure 1 is a top plan view of a door closer, showing the manner inwhich it is used.

Figure 2 is a longitudinal sectional view of .the same.

Figure 3 is a perspective view of the angular bracket or stop member ofthe closer.

The door closer is indicated in general by the letter A and is used toconnect a door B to its door frame C. A hinge 10 is provided connectingthedoor B to. the frame C. As is usual practice in closers of this type,the closer is mounted to a bracket 11 secured by: screws or othersuitable means 12 to the parting stop 13 form- Patented Jan. 12, 1960 3ing a part of the door frame C near the hinged edge of the door. Thebracket 11 supports a pivot 14- which extends through a flattened end 15of the door check plunger rod 16.

A bracket 17 is mounted upon the door B at a point laterally spaced fromthe point of attachment of the bracket 11. This bracket 17 is notched asindicated at 1.9 to accommodate a cooperable bracket 29 on the end ofthe cylinder 21 into which the plunger rod 16 extends. The manner ofconnection, while not or" interest in the present invention, isillustrated in Figur- Z of dra n" ing. The connection is fully describedin my copending application for patent for door check, Serial No.399,544, filed December 21, 1953, now Patent 2,812,533, dated November12, 1957.

The cylinder 21 is provided with an inturned annular flange 22 whichterminates in the cylinder opening 3. A reinforcing plate 24 is mountedinternally of the cylinder and a gasket 25 seals this plate with respectto the inturned flange 22. The plate is provided with a central axialinternally threaded opening The bracket 2'1) is provided with a concaveend 2? which fits against the flange 22.. A threaded plug 3% having anenlarged head 31 extends through an opening 32 in the concave portion 29of the bracket 20, through the aperture 23 and is threaded into theinternally threaded aperture 27 to provide an end closure for thecylinder.

The plug 36 is internally threaded and accommodates a bolt 33 which maybe sufficiently loose to permit some escape of air thereby. The flow ofair' past the bolt 33 depends upon the degree to which this bolt isthreaded into the plug. A spring 34 is interposed between the bolt headand the plug to hold the bolt 33 in an adjusted relation.

A spring retaining member 35 is provided at the op posite end of thecylinder 21 from that described. In the particular form of constructionillustrated, the spring retainer includes a sleeve portion 36 which fitsslidably within the cylinder 21 and which is connected by an offset 37to a smaller diameter portion 39. A split retaining ring 40 is supportedin an annular groove 41 in the cylinder 21 and engages against theoffset 37 to hold the string retainer in place. A ring-shaped flange 42is provided on the end of the smaller diameter portion 39 and acts tohold one end of the spring 43 in position. The other end of the springengages against the plunger which is indicated in general by the numeralThe plunger 44 includes a first Washer 45 which includes a ring-shapedinner portion 46, an offset portion 47, and a ring-shaped outer portion4?. An opening Si is provided through the oflset 47. A flat washer 51 isprovided adjoining the washer .5 and the offset is of proper dimensionsso that an Oring 52 may be accommodated between the washers. A smallpassage 53 is provided through the washer 51.

A flexible washer 54 lies against the washer 51 and a reinforcing washer55 is provided outwardly of the flexible washer 54. The spring 43engages against the reinforcing washer 55.

With this arrangement, it will be seen that as the spring urges theplunger toward the left end of the cylinder as viewed in Figure 2, airfrom the left hand end of the cylinder flows through the passage 50 andtends to expand the O-ring 52 against the cylinder wall. However, ifexcessive pressure is built up, this air will flow through the opening53 and flex the flexible washer 53- sufliciently to permit this air toescape. As a result, the action in closing the door is much smoother andmuch of the bounce usually experienced at the time the air compresses toa point where the movement of the plunger virtually stops is avoided.

If desired, an embossed by-pass 58 may serve to accelerate the closingof the door B near the end of the door closing period. This by-pass 58also permits the ing disadvantages.

door B to be opened more readily during the initial portion of itsopening swing.

One or more indicating lines 56 are provided on the plunger rod 16,these indicating marks providing an indication of the proper setting ofthe stop member 57 to provide a proper original tension of the spring.The member 57 is constructed as best illustrated in Figure 3 of thedrawing. It includes a flat plate portion 59 having an aperture 6%therethrough which encircles the plunger rod 16. The aperture 60 issomewhat larger than the diameter of the plunger rod 16 so that theplate 59 may tilt somewhat out of a plane normal to the axis of theplunger rod and the edges of the aperture may bind against the plungerrod 16. A substantially right angularly extending arm 61 projects fromthe plate 59 and is bent downwardly to some extent to engage against thecap 62 through which the plunger rod 16 and which closes the right handend of the cylinder as indicated in Figure 2. The cap 62, as well as thespring retainer 35, are provided with sufliciently large apertures 53and 64, respectively, to permit the free flow of the air into the righthand end of the cylinder.

If desired, the indicating lines 56 may comprise notches extendingslightly into the surface of the plunger rod so that as the member 57 istilted, it actually engages into the notch and is definitely held fromsliding movement until the cylinder is moved relative to the plungerarm.

The marks 56- are properly spaced to provide varying tension on thespring 43 when the door is closed. For example, three such indicatingmarks 56 may be provided, one for properly tensioning the spring forextremely lightweight doors, another for tensioning the spring formedium weight doors, and the other for tensioning the spring for heavydoors. Obviously, the heavier the door, the more initial tension isplaced upon the spring 43. Thus it will be seen that a simple andeffective closer is provided which is extremely effective for itsintended purpose and which provides all of the advantages of previousstructures without the accompany- The closer moves more effectively thanwould otherwise be the case, and the use of a spring pre-tensioning clipmay be avoided.

In accordance with the patent statutes, I have described the principlesof construction and operation of my door closer, and While I haveendeavored to set forth the best embodiment thereof, I desire to have itunderstood that changes may be made within the scope of the followingclaims without departing from the spirit of my invention.

5 claim:

1. A door cioser including a pair of brackets connected to a door andits frame, respectively, a cylinder connected to one of said brackets, apiston rod extending from one end of the cylinder and connected to theother of said brackets, a piston mounted on said piston d for slidingmovement in said cylinder, and a spring within said cylinder for urgingsaid piston into a predetermined position in which the door is closed,said piston being formed with a peripheral groove, an O-ring in saidgroove, a passageway connecting the base of said groove to the end ofthe cylinder opposite that from which the piston rod extends, movementof said piston in said cylinder during the closing of the door by saidspring acting to compress air in said opposite end of said cylinder,said passage permitting the compressed air to enter said groove toexpand said D-ring.

2. A door closer including a pair of brackets connected to a door andits frame, respectively, a cylir er connected to one of said brackets, apiston rod extene from one end of the cylinder and connected to the0th.. of said brackets, a piston mounted on said piston rod for slidingmovement in said cylinder, and a spring within said cylinder for urgingsaid piston into a predetermined position which the door is closed, saidpiston being formed with a peripheral groove, an Q-ring in said groove,a passageway connecting the base of said groove to the end of thecylinder opposite that from which the piston rod extends, movement ofsaid piston in said cylinder during the closing of the door by saidspring acting to compress air in said opposite end of said cylinder,said passage permitting the compressed air to enter said groove toexpand said O-ring, a flexible washer engaging said piston in surfacecontact therewith, and a reinforcing washer in surface contact with saidflexible washer, said spring engaging against said reinforcing washer,and said piston also having a small passage leading from the base of thegroove to the surface of said flexible washer.

3. The structure described in claim 2 and in which the passage betweenthe base of the groove and said opposite cylinder end is substantiallylarger than the passage from the base of the groove to the surface ofthe flexible washer.

References Cited in the file of this patent UNITED STATES PATENTS289,776 Luton Dec. 4, 1883 1,564,484 Kibele Dec. 8, 1925 2,703,907Newell Mar. 15, 1955 2,808,608 OHare Oct. 8, 1957

